1. Field of the Invention (Technical Field)
The present invention relates to turbocharger compressor assemblies, particularly to means for attaching one turbocharger stage component, such as a compressor assembly, to another stage component, such as a second compressor assembly or a turbocharger center housing rotating assembly.
2. Description of Related Art
Note that where the following discussion refers to a number of publications by author(s) and year of publication, because of recent publication dates certain publications are not to be considered as prior art vis-a-vis the present invention. Discussion of such publications herein is given for more complete background and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
Turbochargers for pressurizing or boosting the intake air stream into an internal combustion engine include several stage components such as an exhaust gas turbine through which the engine's exhaust gas is routed so that the exhaust gas turbine spins within the turbocharger housing. Typically, the exhaust gas turbine is connected via a shaft in a center housing rotating assembly (“CHRA”) to a radial air compressor impeller disposed within a compressor housing so that as the exhaust gas turbine turns, the compressor impeller also turns within the compressor housing and causes intake air to axially enter the compressor housing, go past the impeller, then change direction past a diffuser before entering a compressor housing volute. After the intake air is pressurized or boosted, it exits the turbocharger to be mixed with fuel that is then sent to the engine combustion chamber.
Turbocharger stage components are typically attached to each other via clamp plates, bolts, etc. For example, compressor housings are typically attached to the CHRA via clamp plates and bolts. Such an assembly requires several separate turbocharger parts and the consequent attention to assembly torques required for all fasteners. Therefore, there exists a potential for poor quality assembly as a result of the application of improper torque on the assembly fasteners. There are also greater turbocharger assembly costs as a result of using clamp plates and bolts and greater manufacturing costs associated with threaded holes.
Therefore, there is a need for an inexpensive and precise means to assemble turbocharger stages to each other. Unlike bolts and other fasteners requiring specific assembly torques, the use of snap rings typical in many applications today, including “horse shoe” shaped snap rings, can be simpler and less expensive to utilize if properly applied in the assembly of turbocharger systems.